Ahh I get you. Tbh you don't just need a week. You need space, proper space.
You've been so caught up in their drama. You need space to see clearly for yourself. To get some clarity.
He is upset with you because he's completely entrenched in his affair. He's high on what that is providing for him, and you've put that in jeopardy by contacting her husband.
Please PLEASE stop questioning what they're doing. That's where craziness lies.
Concentrate on you. Create your new family dynamic. Throw yourself into creating some new firsts.
I know you've read chump lady. What you're doing is still fighting for him. Even in a kind of negative way you're still doing some kind of crazy making pick-me dance. Not being critical, I did exactly the same thing, I speak from experience!
The best thing you can do is stay away from their drama, stop being a bit part in their nonsense. Reclaim your world. Your focus on them is keeping their drama triangle alive.
Surviving infidelity is a great forum, go and look at the stories on their just found out thread, you'll read some really wise posters. If you were to post there you'd get lots and lots of support.
It does get better, I promise it does get better but you will need to really gather your courage to cut ties with this idiot! 